The present invention relates to a connection box which collectively connects and distributes wire-harness in the case that wire harness is arranged in a vehicle.
The connection box is substantially formed by piling a single-layered or a multi-layered circuit board in which bus bar and electric wires are arranged so as to constitute a desired circuit, on a plane wiring board, and by covering the board by an upper cover and an under cover. A control boardboard constituting an electronic control portion is mounted on the board mentioned above. The control base boardboard has an insulating board, and electronic parts such as a resistor, a coil, a relay, a fuse and the like are provided thereon. The control base board is connected to a predetermined circuit of the board.
The relay provided on the control base board could employ a mechanical type using an electromagnetic solenoid in order to be capable of accommodating to a comparatively large electric current. The mechanical relay has an electromagnetic solenoid to produce a large amount of heat.